Device for promoting constant tension in all warp threads of a circular weaving loom



' Sept. 19, 1967 v O A, MALCH'AIR 3,342,219

DEVICE FOR PROMOTING CON STANT TENSION IN ALL WARP THREADS OF A CIRCULAR WEAVING LOOM Filed Jan. 25, 1965 4 Sheets-Sheet l INVENTOR.

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' wwcx g ATTOkNEi SS Filed Jan. 25, 1965 Sept. 19,1967

A. MALCHA'IR 7 DEVICE FOR PROMOTING CONSTANT TENSION IN ALL WARP THREADS OF A CIRCULAR WEAVING LOOM 4 Sheets-Sheet 2 INVENTOR A. Mala/70.11!

ATTomNEds A. MALCHAIR 3,342,219 FOR PROMOTING CONSTANT TENSION IN ALL WARP THREADS OF A CIRCULAR WEAVING LOOM DEVICE} 4 Sheets-Sheet 5 Filed Jan. 25, 1965 INVENTOR. A./1c1Zc/mir ATT'QYLN E95 Fm n Sept. 19, 1967 -A. MALCHAIR 3,342,219

DEVICE FOR PROMOTING CONSTANT TENSION IN ALL WARP I THREADS OF A CIRCULAR WEAVING LOOM Filed Jan v25, 1965 4 Sheets-$11eet 4 INVENTOR.

ma g w TTQfLNESS United States Patent Ofiice 3,342,219 DEVICE FOR PROMOTING CONSTANT TENSION IN ALL WARP THREADS OF A CIRCULAR WEAVING LOOM Armand Malchair, Herstal, Belgium, assignor to Suciete Anonyme Iwan Simonis, S.A., Verviers, Belgium Filed Jan. 25, 1965, Ser. No. 427,660 Claims priority, application Netherlands, Jan. 28, 1964, 640,633 3 Claims. (Cl. 139-13) It is a well known fact that, in weaving looms, it is indispensable to provide for the warp threads a tension which is as constant as possible, in order to prevent malformations of the fabric.

This problem is particularly acute in circular weaving looms and, to a still higher degree, in those for large weaving diameters, fed by a reduced number of cylindrical warp beams. In fact, the warp threads leave each beam in a straight line, respectively a generatrix of the beam, and must reach a circular arc the actual length of which is substantially larger than the length of each one of aforesaid beams. It follows that, for each beam, all pairs of threads made up of two warp threads symmetrically disposed with respect to a vertical plane containing the general axis of the weaving loom and perpendicular to the beam, have different lengths.

Such differences may acquire a considerable extent so that one and the same effort applied to each of the warp threads gives rise to different stretchings of the latter, which stretchings are namely a function of the length of the threads. These stretchings, when the Warp threads are no longer subjected to stresses, give in turn rise to variable tensions in the fabric which has been formed, thus causing malformations of the latter. It should also be noticed that this state of affairs gets worse when the fabric is laid flat.

The object of the present invention is to provide a device by means of which it is possible to feed the warp threads, starting from an ordinary cylindrical beam, onto a circular arc the actual length of which is greater than that of the beam, thus avoiding the disadvantages mentioned above.

One device according to the present invention mainly consists of a static curved part for guiding the warp threads, substantially inscribed in the imaginary cylindrical surface, tangent to the compensator ring, whose shape is established in such way that all the warp threads of one and the same beam have the same length which is at least equal to the tangent leading from one extremity of the circular are fed by aforesaid beam to the corresponding upper extremity of the cylindrical surface of aforesaid beam.

According to another characteristic feature of the present invention, a static curved guiding part is provided with means for avoiding any crossing of the warp threads.

It should be noticed that in circular weaving looms a device is already known for avoiding such crossing of the threads fed from a cylindrical beam onto a circular arcof same length. This known device transforms the plane surface of a sheet of threads when they leave the beam into a cylindrical surface and this in such way that each thread follows the line of shortest possible distance, measured along the thread between the point where it leaves the beam and the point when it reaches the circular are which is being fed.

But this device can hardly be applied when the actual length of the circular are fed by a beam is greater than the length of the latter, Whilst there remains an important difference of length between aforesaid threads.

In order to explain more clearly the characteristic features and advantages of the device according to the present invention, an example of embodiment of the latter is 3,342,219 Patented Sept. 19, 1967 described hereafter by way of illustration and without implying any restrictive nature, reference being made to the appended drawings of which:

FIGURE 1 is a diagrammatic top view, with partial cut, of a weaving loom with three beams equipped with the device conforming to the present invention;

FIGURE 2 is a diagrammatic radial section by a plane whose trace follows the straight line IIII of FIG URE 1;

FIGURE 3 is a diagrammatic perspective view, illustrating the function of the device according to the present invention;

FIGURE 4 is a section by a plane whose trace follows the straight line 1VIV of FIGURE 3;

FIGURE 5 is a perspective view of part of the device according to the present invention, illustrating more particularly the means provided for preventing a crossing of the warp threads;

FIGURE 6 is a view in the direction of arrow F5 of FIGURE 4;

FIGURE 7 is a section by a plane whose trace follows the straight line VII-VII of FIGURE 4.

The circular weaving loom to which the device according to the present invention is being applied is one of large diameter, fed by three beams. It namely comprises the following major parts: the beams 1 and their wire tension probing thread-holders 2, the compensators 3, the mechanisms for the guiding element 4, the shuttle holders 5, the shuttles 6, the weaving ring 7, the armature mechanism 8, the selector 9, the drum 10, the tension roller 11 and the winding drum for the fabric 12.

The sum of the lengths of the three beams 1 is less than the developed width of an imaginary vertical cylindrical surface which is externally tangent to the ring of compensators 3. This term is used to define the circumferential length of the ring of compensators at its point of contact with the threads.

The warp threads 13 leave the beam 1 and must come are equal to of the ring of compensators 3, whereby R stands for the radius of aforesaid imaginary cylindrical surface.

The abovementioned importance of the differences in length of aforesaid warp threads 13 will clearly appear from the example below:

Let R, radius of aforesaid imaginary cylindrical surface, be equal to cm.; a be equal to 70 cm., the difference in level between the axis of the tension probing thread-holder 2 and the plane containing the contact circumference between aforesaid imaginary cylindrical surface and the ring of compensators 3; .b equal to 50 cm., be the shortest distance between the axis of aforesaid probing thread-holder 2 and aforesaid imaginary surface; and 2c, equal to 200 cm., the length of the beam 1. Supposing moreover that the warp threads 13 take the shortest path between aforesaid probing thread-holder 2 and the ring of compensators 3, the difference D in length of the warp threads may reach:

As the stretching (and the tension) of the threads is proportional to their length, the equality in length of all warp threads 13 is therefore of major importance. Now, in the example which was worked out above, no account has been taken of the fact that the sheet of warp threads 13 which reaches the tension probing thread-holder 2 as a flat sheet must be converted into a cylindrical sheet before reaching the circle of compensators. Devices consisting of curved rods, already known in the art, make it possible to effect this transformation but they do not take any account of the differences in length of the warp threads, being intended to be fitted into circular weaving looms in which each beam feeds a circular arc whose length is equal to that of the beam.

The device according to the present invention does away with this drawback. It substantially consists of a beam 1, a curved rod 14 the horizontal projection of which coincides with the horizontal projection of aforesaid imaginary cylindrical surface, whereby the curvature of aforesaid rod 14 is such that, for each warp thread, the sum of the distance measured on the one hand between the tension probing thread-holder 2 and aforesaid rod 14 and on the other hand from aforesaid rod 14 to the circle of compensators is constant, i.e., equal to the length of the external threads called respectively 15 and 16 in FIGURE 3.

The length of aforesaid rod 14 is such that the generatrices of aforesaid imaginary cylindrical surface, passing through its extremities, determine on the contact circumference of aforesaid surface with the ring of compensators an arc equal to whereby n is the number of beams provided on the loom in question.

Rod 14 is fastened at its ends to any appropriate rigid part of the loom, such as, for instance, the supports 17 of the circular platform 18.

In order to prevent the warp threads 13 from crossing, rod 14 will preferably be provided with a longitudinal comb.

In the form of embodiment illustrated in FIGURES 4 to 7, this comb consists of sections of trapezoidal springs 19 disposed in each others extension along aforesaid rod 14. With this purpose in view, the latter is provided with radial axes 20 onto which are slid square tube lengths 21 fastened to aforesaid axes 20 by axes 22. The corresponding extremities of two adjacent spring sections 19 are fastened respectively to opposite faces 23 and 24 of a tube length 21. In this way, the warp threads 13 are maintained at the proper distance from each other with a minimum of stress.

By means of the device according to the present invention, it is now possible to eliminate, in .a circular weaving loom of large diameter using but a limited number 4 of beams the sum of whose lengths is less than the circumferential length of the ring of compensators, any stresses in the fabric as well as the consequent faulty results, the retraction of the warp threads being uniform once the fabric has been formed and spread out flat.

It is evident that any modification of form or dimension applied to this device remains part of the invention as long as the principles defined above are upheld.

What we claim is:

1. In a circular weaving loom having a central ring of compensators, a plurality of thread-carrying beams located around and extending tangentially to said ring of compensators, the circumferential length of said ring of compensators being greater than the sum of the lengths of said beams, and a plurality of elongated thread holders, each thread holder being located adjacent a separate beam and receiving threads unwound from that beam, the improvement which comprises a curved static element aligned with said ring of compensators and having a curvature every point of which is so spaced from said thread holders and said ring of compensators that every thread extending from a thread holder to the static element and from the static element to the ring of compensators has the same length.

2. Device according to claim 1 characterized by the fact that said curved static element comprises a combshaped part intended for maintaining the proper spacing of the threads and for avoiding any risk that the latter might cross.

3. Device according to claim 2, characterized by the fact that aforesaid comb-shaped part consists of a plurality of trapezoidal spring sections.

References Cited UNITED STATES PATENTS 7 Re. 8,952 11/1879 Greenough 13916 603,407 5/ 1898 Palmer 13997 1,444,590 2/1923 Crespi 139-16 2,002,091 5/1935 Jabouley 139-13 2,087,322 7/1937 Jabouley 139-13 2,141,679 12/1938 Balsach 13913 2,433,190 12/1947 Ancet 13913 2,679,264 5/1954 Dunod 139-13 2,747,618 5/1956 Catry et al. 139-13 FOREIGN PATENTS 699,084 11/1940 Germany.

MERVIN STEIN, Primary Examiner. J. KEE CHI, Assistant Examiner,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,342,219 September 19, 1967 Armand Malchair It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the heading to the printed specification, lines 5 and 6, for assignor to Societe Anonyme Iwan Simonis, S.A. Verviers, Belgium" read assignor, by mesne assignments, to Peltzer G Fils S.A. societe anonyme, Verviers, Belgium a company of Belgium Signed and sealed this 17th day of December 1968.

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer 

1. IN A CIRCULAR WEAVING LOOM HAVING A CENTRAL RING OF COMPENSATORS, A PLURALITY OF THREAD-CARRYING BEAMS LOCATED AROUND AND EXTENDING TANGENTIALLY TO SAID RING OF COMPENSATORS, THE CIRCUMFERENTIAL LENGTH OF SAID RING OF COMPENSATORS BEING GREATER THAN THE SUM OF THE LENGTH OF SAID BEAMS, AND A PLURALITY OF ELONGATED THREAD HOLDERS, EACH THREAD HOLDER BEING LOCATED ADJACENT A SEPARATE BEAM AND RECEIVING THREADS UNWOUND FROM THAT BEAM, THE IMPROVEMENT WHICH COMPRISES A CURVED STATIC ELEMENT ALIGNED WITH SAID RING OF COMPENSATORS AND HAVING A CURVATURE EVERY POINT OF WHICH IS SO SPACED FROM SAID THREAD HOLDERS AND SAID RING OF COMPENSATORS THAT EVERY THREAD EXTENDING FROM A THREAD HOLDER TO THE STATIC ELEMENT AND FROM THE STATIC LEMENT TO THE RING OF COMPENSATORS HAS THE SAME LENGTH. 